Storage control apparatus and computer-readable storage medium storing storage control program

1. A storage control apparatus comprising: a memory that stores mapping management information indicating mappings between each of a plurality of divided regions created by dividing logical storage space on a storage apparatus and one of a plurality of identification numbers each representing a different write frequency; and a processor that executes a process including: identifying, upon request for a data write to a write address included in any of the plurality of divided regions, an identification number associated with a divided region including the write address amongst the plurality of identification numbers based on the mapping management information, appending the identified identification number to a first write request for the write address, and transmitting the first write request with the identified identification number appended thereto to the storage apparatus, measuring a write frequency of each of the plurality of divided regions, updating the mappings indicated by the mapping management information based on results of the measuring, the updating including associating, when the plurality of identification numbers is smaller in number than the plurality of divided regions, at least one of the plurality of identification numbers with two or more of the plurality of divided regions, and identifying, upon request for a data write to the write address after the updating, an identification number associated with the divided region including the write address amongst the plurality of identification numbers based on the mapping management information, appending the identified identification number to a second write request for the write address, and transmitting the second write request with the identified identification number appended thereto to the storage apparatus.

2. The storage control apparatus according to claim 1 , wherein: the plurality of identification numbers is information used to control the storage apparatus to write write data to a different one of a plurality of management regions according to an identification number appended to the write data, and each of the plurality of management regions is a unit of data deletion, included in physical storage space on the storage apparatus.

3. The storage control apparatus according to claim 1 , wherein: the updating is performed each time a cumulative amount of data written to the storage apparatus increases by a predetermined amount.

4. The storage control apparatus according to claim 1 , wherein: the process further includes: acquiring, when an amount of free space in physical storage space on the storage apparatus has fallen below a predetermined amount, a total data amount of data with each of the plurality of identification numbers appended thereto at time of writing amongst data written to the storage apparatus, identifying, amongst the plurality of identification numbers, a specific identification number whose total data amount exceeds a predetermined reference amount, and causing the storage apparatus to implement garbage collection on data with the specific identification number appended thereto at time of writing.

5. The storage control apparatus according to claim 4 , wherein: the memory further stores data amount management information which registers a write data amount corresponding to each of the plurality of identification numbers, the process further includes adding, each time a write request with one of the plurality of identification numbers appended thereto is transmitted to the storage apparatus, a size of data involved in the write request to the write data amount corresponding to the appended identification number, and the acquiring includes reading, from the data amount management information as the total data amount, the write data amount corresponding to each of the plurality of identification numbers at time of the acquiring.

6. The storage control apparatus according to claim 4 , wherein: the process further includes: identifying, amongst the plurality of divided regions, a specific divided region which is associated with the specific identification number before a latest update of the mappings and for which no write request has been issued after the latest update of the mappings, identifying, based on the mapping management information, a current identification number currently associated with the specific divided region amongst the plurality of identification numbers, and reading, from the storage apparatus, data written to the specific divided region before the latest update of the mappings, appending the current identification number to the read data, and rewriting, to the storage apparatus, the read data with the current identification number appended thereto.

7. A non-transitory computer-readable storage medium storing a storage control program that causes a computer to execute a process comprising: identifying, upon request for a data write to a write address included in any of a plurality of divided regions created by dividing logical storage space on a storage apparatus, an identification number associated with a divided region including the write address amongst a plurality of identification numbers each representing a different write frequency based on mapping management information indicating mappings between each of the plurality of divided regions and one of the plurality of identification numbers, appending the identified identification number to a first write request for the write address, and transmitting the first write request with the identified identification number appended thereto to the storage apparatus, measuring a write frequency of each of the plurality of divided regions, updating the mappings indicated by the mapping management information based on results of the measuring, the updating including associating, when the plurality of identification numbers is smaller in number than the plurality of divided regions, at least one of the plurality of identification numbers with two or more of the plurality of divided regions, and identifying, upon request for a data write to the write address after the updating, an identification number associated with the divided region including the write address amongst the plurality of identification numbers based on the mapping management information, appending the identified identification number to a second write request for the write address, and transmitting the second write request with the identified identification number appended thereto to the storage apparatus.

8. The non-transitory computer-readable storage medium according to claim 7 , wherein: the plurality of identification numbers is information used to control the storage apparatus to write write data to a different one of a plurality of management regions according to an identification number appended to the write data, and each of the plurality of management regions is a unit of data deletion, included in physical storage space on the storage apparatus.

9. The non-transitory computer-readable storage medium according to claim 7 , wherein: the updating is performed each time a cumulative amount of data written to the storage apparatus increases by a predetermined amount.

10. The non-transitory computer-readable storage medium according to claim 7 , wherein: the process further includes: acquiring, when an amount of free space in physical storage space on the storage apparatus has fallen below a predetermined amount, a total data amount of data with each of the plurality of identification numbers appended thereto at time of writing amongst data written to the storage apparatus, identifying, amongst the plurality of identification numbers, a specific identification number whose total data amount exceeds a predetermined reference amount, and causing the storage apparatus to implement garbage collection on data with the specific identification number appended thereto at time of writing.

11. The non-transitory computer-readable storage medium according to claim 10 , wherein: the process further includes: storing, in a memory, data amount management information which registers a write data amount corresponding to each of the plurality of identification numbers, and adding, each time a write request with one of the plurality of identification numbers appended thereto is transmitted to the storage apparatus, a size of data involved in the write request to the write data amount corresponding to the appended identification number, and the acquiring includes reading, from the data amount management information as the total data amount, the write data amount corresponding to each of the plurality of identification numbers at time of the acquiring.

12. The non-transitory computer-readable storage medium according to claim 10 , wherein: the process further includes: identifying, amongst the plurality of divided regions, a specific divided region which is associated with the specific identification number before a latest update of the mappings and for which no write request has been issued after the latest update of the mappings, identifying, based on the mapping management information, a current identification number currently associated with the specific divided region amongst the plurality of identification numbers, and reading, from the storage apparatus, data written to the specific divided region before the latest update of the mappings, appending the current identification number to the read data, and rewriting, to the storage apparatus, the read data with the current identification number appended thereto.